<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>image</title>

    <!-- Bootstrap -->
    <link href="bootstrap.min.css" rel="stylesheet">
    <style type="text/css">

    </style>

</head>
<body>
    <div class="container">
        <img src="2.jpg" alt="" class="img-responsive" alt="This is a picture"/>

        <!--图片形状-->
        <br/>
        <br/>
        <img src="2.jpg" alt="" class="img-rounded" alt="This is a picture"/>
        <img src="2.jpg" alt="" class="img-circle" alt="This is a picture"/>
        <img src="2.jpg" alt="" class="img-thumbnail" alt="This is a picture"/>
    </div>
</body>
</html>